434 MOLLUSCA. 
Pyrgulopsis (?) patzcuarensis, Pilsbry, in Nautilus, v. p. 9 (1891) *°; Proc. Acad. Phil. 1891, 
p. 380, t. 15. fig. 8°. 
Hab. Centra Mexico: Lake Patzcuaro (Heilprin *° 31). 
EK. Mexico: Vera Cruz (Strebel 9). 
ANTILLES: Vieque (Blauner *5). 
Var. crystallina. 
Paludina crystallina, Pfr. in Wiegmann’s Archiv f. Naturg. 1840, p. 253°; Philippi, Abbild. 
neuer Conch. i., Paludina, p. 118, t. 1. fig. 18°*; Kiister, in Martini & Chemnitz, Syst. 
Conch.-Cab. ed. 2, Paludina, p. 50, t. 10. figg. 7, 8. 
Amnicola crystallina, Shuttleworth, Mittheil. naturf. Ges. Bern, 1854 (Diagn. never Moll. vii.), 
p. 159”. 
Hydrobia cristallina (Pfr.), v. Frauenf., Verh. zool.-bot. Ges. Wien, xiv. p. 593 (Verz. d. Namen 
v. Paludina, p. 33) (1864) °°. 
Paludina anthracina, Mighels, Proc. Bost. Soc. Nat. Hist. ii. p. 22 (1845) *. 
Paludina jamaicensis, C. B. Adams, Contrib. Conch. i. p. 42 (1849). 
Paludina cisternicola, Morelet, Test. Noviss. ii. p. 21 (1851) *. 
Amanicola coronata, var. y. inermis, Fisch. Journ. de Conch. viii. p. 363 (1860) *°. 
Hydrobia coronata, var., Strebel, Beitr. Mex. Land- und Stissw.-Conch. i. p. 84”. 
Amnicola coronata, var. 8. crystallina, Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i. p. 266, 
t. 1. figg. 6d, 6e”. 
Pyrgulopsis nicaraguanus, varr., and wrighti, varr., Ancey, Bull. Soc. Malac. Fr. v. pp. 196, 197, 200 *. 
Hab. EK. Mexico: Vera Cruz (Strebel 41). 
YucaTAN: in cisterns in the city of Campeche (Morelet *°) ; Sisal (Morelet 42), 
SaLvapor: Lake Coatepeque (Morelet **, Ancey *?). 
W. Nicaragua: Lake of Nicaragua (Ancey 4°). 
ANTILLES: Cuba *, Jamaica °°, Vieque *, Tortola 37, Guadeloupe. 
Operculum corneous, subspiral, radiately marked (Tate). 
Strebel has also found living specimens near Vera Cruz in ditches near the railway, 
also in a shallow one with slowly-flowing, badly-smelling water, receiving the outlet of 
gasworks ; but he cannot state to which variety these examples belong. At all events 
his observation corroborates the fact stated by me in 1858, that the animals of this 
genus are rather indifferent to the quality of the water. 
7. Amnicola palomaensis. 
Bythinella palomaensis, Pilsbry, in Nautilus, ix. p. 68 (1895) *, 
Hab. N. Cenrrat Mexico: Laguna de Palomas, State of Chihuahua (Dr. E. A. Mearns'). 
The author refers this shell to the genus Bythinella, which is numerously repre- 
sented in Europe, the species being found chiefly in springs, the number of whorls (4) 
and the obtuse apex agreeing well with that division. He says that B. ( Potamiopsis) 
binneyi, Tryon, and B. brevissima, Pilsbry, are conchologically its nearest allies among 
the North-American forms. 
